Batteries, such as alkaline batteries, are commonly used as electrical energy sources. Generally, a battery contains a negative electrode and a positive electrode. The negative electrode contains an active material (e.g., zinc particles) that can be oxidized; and the positive electrode contains an active material (e.g., manganese dioxide) that can be reduced. The active material of the negative electrode is capable of reducing the active material of the positive electrode. In order to prevent direct reaction of the active material of the negative electrode and the active material of the positive electrode, the electrodes are electrically isolated from each other by a separator.
When a battery is used as an electrical energy source in a device, such as a cellular telephone, electrical contact is made to the electrodes, allowing electrons to flow through the device and permitting the respective oxidation and reduction reactions to occur to provide electrical power. An electrolyte in contact with the electrodes contains ions that flow through the separator between the electrodes to maintain charge balance throughout the battery during discharge.